Alcohol content

[nickh42]

Hi all.
This has long been bothering me as to how to tell the alcohol content without measuring the OG. Today I tried an experiment and I was wondering if I'm on the right lines.
I weighed a 500 ml bottle of claimed 6.6% beer poured into my pint mug. Then I weighed in the same mug to the marked point of where the beer was with water. The difference in weight I divided by 6.6 and came up with 1% alcohol being 0.15775 heavier than water.
So according to my calculation, my home brew is 6.73%
Is there any 'strength' in my supposition or am I barking up the wrong tree?
Cheers all, chin chin.
Nick

 

[VikeMan]

I'm not sure I'm following everything you said, but it might not matter. If beer were nothing but water and ethanol, you could calculate alcohol content by weighing the beer. But it's not, so you can't.

 

[nickh42]

Thank you vikeman.
Had a feeling that was going to be too easy

 

[BrewnWKopperKat]

alcohol content without measuring the OG

There is a tool to approximate OG/ABV from current Brix & FG: Homebrew Refractometer Calculator . It may be intended to be used just pre-packaging, and not post-packaging.